1. Field of the Invention
The invention relates to a method of exchanging data in the form of telegrams in a network having a master station, at least one subscriber station and a common data channel according to a hierarchical token-passing principle with controlled assignment of a control token.
2. Discussion of Background
The published patent applications EP-0,208,872, EP-0,231,457, EP-0,236,558 and EP-0,238,813 disclose signal transmission methods which are particularly suited to data transmission on the lines of a low-voltage and/or medium-voltage system. They are distinguished in that they are matched to the time- and frequency-dependent interference characteristics of the transmission channel, which results in a greatly improved availability of individual data connections for, at the same time, a small transmitting power.
In order to realize a control system on low-voltage and medium-voltage systems, however, in addition to as interference-free a signal transmission as possible between an individual transmitter and a receiver, a method for controlling the data exchange between a plurality of subscribers is also required. In particular the location-dependent and time-dependent transmission security of the common data channel must be taken into account here.
An important point is the flexibility of the system. It should be possible to expand the network without great outlay.